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timers: do not retain a reference to the async store after firing #53443

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timers: do not retain a reference to the async store after firing #53443

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4 changes: 3 additions & 1 deletion lib/internal/async_hooks.js
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Original file line number Diff line number Diff line change
Expand Up @@ -105,6 +105,7 @@ const before_symbol = Symbol('before');
const after_symbol = Symbol('after');
const destroy_symbol = Symbol('destroy');
const promise_resolve_symbol = Symbol('promiseResolve');
const async_local_storage_context_symbol = Symbol('kAsyncLocalStorageContext');
const emitBeforeNative = emitHookFactory(before_symbol, 'emitBeforeNative');
const emitAfterNative = emitHookFactory(after_symbol, 'emitAfterNative');
const emitDestroyNative = emitHookFactory(destroy_symbol, 'emitDestroyNative');
Expand Down Expand Up @@ -595,7 +596,8 @@ module.exports = {
symbols: {
async_id_symbol, trigger_async_id_symbol,
init_symbol, before_symbol, after_symbol, destroy_symbol,
promise_resolve_symbol, owner_symbol,
promise_resolve_symbol, async_local_storage_context_symbol,
owner_symbol,
},
constants: {
kInit, kBefore, kAfter, kDestroy, kTotals, kPromiseResolve,
Expand Down
30 changes: 22 additions & 8 deletions lib/internal/async_local_storage/async_hooks.js
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Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,11 @@ const {
const {
validateObject,
} = require('internal/validators');
const {
symbols: {
async_local_storage_context_symbol,
},
} = require('internal/async_hooks');

const {
AsyncResource,
Expand All @@ -23,6 +28,11 @@ const RunScope = require('internal/async_local_storage/run_scope');
const { kEmptyObject } = require('internal/util');

const storageList = [];

function getOrCreateResourceStore(resource) {
return resource[async_local_storage_context_symbol] ??= { __proto__: null };
}

const storageHook = createHook({
init(asyncId, type, triggerAsyncId, resource) {
const currentResource = executionAsyncResource();
Expand Down Expand Up @@ -91,16 +101,18 @@ class AsyncLocalStorage {

// Propagate the context from a parent resource to a child one
_propagate(resource, triggerResource, type) {
const store = triggerResource[this.kResourceStore];
const store = triggerResource[async_local_storage_context_symbol]?.[this.kResourceStore];
if (this.enabled) {
resource[this.kResourceStore] = store;
const resourceStore = getOrCreateResourceStore(resource);
resourceStore[this.kResourceStore] = store;
}
}

enterWith(store) {
this._enable();
const resource = executionAsyncResource();
resource[this.kResourceStore] = store;
const resourceStore = getOrCreateResourceStore(resource);
resourceStore[this.kResourceStore] = store;
}

run(store, callback, ...args) {
Expand All @@ -112,14 +124,15 @@ class AsyncLocalStorage {
this._enable();

const resource = executionAsyncResource();
const oldStore = resource[this.kResourceStore];
const resourceStore = getOrCreateResourceStore(resource);
const oldStore = resourceStore[this.kResourceStore];

resource[this.kResourceStore] = store;
resourceStore[this.kResourceStore] = store;

try {
return ReflectApply(callback, null, args);
} finally {
resource[this.kResourceStore] = oldStore;
resourceStore[this.kResourceStore] = oldStore;
}
}

Expand All @@ -138,10 +151,11 @@ class AsyncLocalStorage {
getStore() {
if (this.enabled) {
const resource = executionAsyncResource();
if (!(this.kResourceStore in resource)) {
const resourceStore = resource[async_local_storage_context_symbol];
if (resourceStore === undefined || !(this.kResourceStore in resourceStore)) {
return this.#defaultValue;
}
return resource[this.kResourceStore];
return resourceStore[this.kResourceStore];
}
return this.#defaultValue;
}
Expand Down
86 changes: 75 additions & 11 deletions lib/internal/timers.js
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Original file line number Diff line number Diff line change
Expand Up @@ -87,6 +87,9 @@ const {
immediateInfo,
timeoutInfo,
} = binding;
const {
enqueueMicrotask,
} = internalBinding('task_queue');

const {
getDefaultTriggerAsyncId,
Expand All @@ -97,6 +100,9 @@ const {
emitBefore,
emitAfter,
emitDestroy,
symbols: {
async_local_storage_context_symbol,
},
} = require('internal/async_hooks');

// Symbols for storing async id state.
Expand Down Expand Up @@ -125,6 +131,36 @@ const AsyncContextFrame = require('internal/async_context_frame');

const async_context_frame = Symbol('kAsyncContextFrame');

function removeStoresFromResource(resource) {

@Flarna Flarna Jun 18, 2026 •
edited
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I think this should be extended to somthing like this to cover also the async context frame variant of ALS:

function removeStoresFromResource(resource) {
  if (AsyncContextFrame.enabled) {
    if (resource[async_context_frame] !== undefined) {
      resource[async_context_frame] = undefined;
    }
  } else {
    if (resource[async_local_storage_context_symbol] !== undefined) {
      resource[async_local_storage_context_symbol] = undefined;
    }
  }
}

if (!AsyncContextFrame.enabled &&
resource[async_local_storage_context_symbol] !== undefined) {
resource[async_local_storage_context_symbol] = undefined;
}
}

function cleanTimer(timer) {
removeStoresFromResource(timer);
timer._onTimeout = undefined;
timer._timerArgs = undefined;
}

function cleanImmediate(immediate) {
removeStoresFromResource(immediate);
immediate._onImmediate = undefined;
immediate._argv = undefined;
}

function enqueueRemoveStoresFromResource(resource) {
enqueueMicrotask(() => removeStoresFromResource(resource));
}

function enqueueRemoveStoresIfNotReinserted(resource) {
enqueueMicrotask(() => {
if (!resource._idleNext && !resource._idlePrev)
removeStoresFromResource(resource);
});
}

// *Must* match Environment::ImmediateInfo::Fields in src/env.h.
const kCount = 0;
const kRefCount = 1;
Expand Down Expand Up @@ -498,14 +534,22 @@ function getTimerCallbacks(runNextTicks) {
const asyncId = immediate[async_id_symbol];
emitBefore(asyncId, immediate[trigger_async_id_symbol], immediate);

let threw = true;
try {
const argv = immediate._argv;
if (!argv)
immediate._onImmediate();
else
immediate._onImmediate(...argv);
threw = false;
} finally {
immediate._onImmediate = null;
if (threw) {
immediate._onImmediate = undefined;
immediate._argv = undefined;
enqueueRemoveStoresFromResource(immediate);
} else {
cleanImmediate(immediate);
}

emitDestroy(asyncId);

Expand Down Expand Up @@ -577,6 +621,8 @@ function getTimerCallbacks(runNextTicks) {
if (!timer._destroyed) {
timer._destroyed = true;

cleanTimer(timer);

if (timer[kHasPrimitive])
delete knownTimersById[asyncId];

Expand All @@ -599,26 +645,42 @@ function getTimerCallbacks(runNextTicks) {
start = binding.getLibuvNow();
}

let threw = true;
try {
const args = timer._timerArgs;
if (args === undefined)
timer._onTimeout();
else
ReflectApply(timer._onTimeout, timer, args);
threw = false;
} finally {
if (timer._repeat && timer._idleTimeout !== -1) {
timer._idleTimeout = timer._repeat;
insert(timer, timer._idleTimeout, start);
} else if (!timer._idleNext && !timer._idlePrev && !timer._destroyed) {
timer._destroyed = true;

if (timer[kHasPrimitive])
delete knownTimersById[asyncId];

if (timer[kRefed])
timeoutInfo[0]--;

emitDestroy(asyncId);
} else if (!timer._idleNext && !timer._idlePrev) {
if (timer._destroyed) {
timer._onTimeout = undefined;
timer._timerArgs = undefined;
if (threw)
enqueueRemoveStoresIfNotReinserted(timer);
else
removeStoresFromResource(timer);
} else {
if (threw)
enqueueRemoveStoresIfNotReinserted(timer);
else
removeStoresFromResource(timer);

timer._destroyed = true;

if (timer[kHasPrimitive])
delete knownTimersById[asyncId];

if (timer[kRefed])
timeoutInfo[0]--;

emitDestroy(asyncId);
}
}
}

Expand Down Expand Up @@ -703,6 +765,8 @@ module.exports = {
kRefed,
kHasPrimitive,
initAsyncResource,
cleanImmediate,
cleanTimer,
setUnrefTimeout,
getTimerDuration,
immediateQueue,
Expand Down
12 changes: 10 additions & 2 deletions lib/timers.js
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Original file line number Diff line number Diff line change
Expand Up @@ -38,6 +38,8 @@ const {
async_id_symbol,
Timeout,
Immediate,
cleanImmediate,
cleanTimer,
decRefCount,
immediateInfoFields: {
kCount,
Expand Down Expand Up @@ -69,9 +71,12 @@ const {

// Remove a timer. Cancels the timeout and resets the relevant timer properties.
function unenroll(item) {
if (item._destroyed)
if (item._destroyed) {
cleanTimer(item);
return;
}

const wasEnrolled = item._idleNext !== null || item._idlePrev !== null;
item._destroyed = true;

if (item[kHasPrimitive])
Expand Down Expand Up @@ -99,6 +104,9 @@ function unenroll(item) {
decRefCount();
}

if (wasEnrolled)
cleanTimer(item);

// If active is called later, then we want to make sure not to insert again
item._idleTimeout = -1;
}
Expand Down Expand Up @@ -238,7 +246,7 @@ function clearImmediate(immediate) {

emitDestroy(immediate[async_id_symbol]);

immediate._onImmediate = null;
cleanImmediate(immediate);

immediateQueue.remove(immediate);
}
Expand Down
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